Surface neural recording and stimulation involves placing an electrode array directly on the surface of the targeted neural tissue. The electrode array typically includes electrode sites that sense electrical activity in the tissue and can be used to assess neuronal activity. The electrode sites can also deliver small electrical currents to the tissue and can be used to stimulate neuronal activity. For example, electrocorticography, or ECoG, involves placing an electrode array directly on the cerebral cortex, the outer surface of the brain. ECoG can be used in epilepsy mapping procedures conducted to identify and locate diseased tissue in preparation for surgical resection of the diseased tissue. However, conventional surface arrays are large and have a limited spatial resolution that reduces the precision of sensed electrical activity or stimulated electrical activity, resulting in reduced precision of gathered neural activity information or activation. Thus, there is a need in the neural devices field to create an improved neural device with modular electrode arrays. This invention provides such an improved neural device.